|  | 4.4 | Explain Layer 2 Design
| 4.4.1 | Common Layer 2 devices and their impact on network domains

As you learned previously in the "LAN Switching" chapter and in the "VLANs" chapter, the purpose of Layer 2 devices in the network is to provide flow control, error detection, error correction, and to reduce congestion in the network. The two most common Layer 2 devices (other than the NIC, which every host on the network must have) are bridges and LAN switches. Devices at this layer determine the size of the collision domains and broadcast domains. This section concentrates on the implementation of LAN switching at Layer 2.
| Threaded Case Study
Washington Project: Layer 2 Design goals

The following are Layer 2 LAN topology design goals for the sites of the Washington School District network:

- You should install LAN switching devices that use microsegmentation in order to reduce the collision domain size.
- You should create VLANs and unique broadcast domains based on user workgroups.

| Web Links
| Designing Switched LAN Internetworks
| Broadcasts in Switched LAN Internetworks